[Screening for tetrahydrobiopterin metabolic disorders and related gene analysis among the patients with motor disturbance and mental retardation].

Abstract

OBJECTIVE:

To study the incidence of various enzyme deficiency in tetrahydrobiopterin (BH4) metabolism and the related gene mutation among the patients with motor disturbance and mental retardation.

METHODS:

One hundred patients with unknown motor disturbance and mental retardation were referred to this study. All patients were performed by phenylalanine (Phe) and BH4 loading test, urinary pterin analysis and dihydropteridine reductase (DHPR) activity. Some patients received the dopa treatment for diagnosis of dopa-responsive dystonia (DRD). The analysis of GTP cyclohydrolase 1 gene (GCH1) mutation for DRD patients and the analysis of 6-pyruvoyl tetrahydropterin synthase (PTS) gene mutations for PTS deficient patients were done under the consent from their parents.

RESULTS:

Seventy of 100 patients had normal basic blood Phe levels, six (6%) patients were diagnosed as DRD. Thirty patients had hyperphenylalaninemia (HPA), eight (8%) were diagnosed as PTS deficiency and 22(22%) were diagnosed as phenylalanine hydroxylase (PAH) deficiency. All patients had normal DHPR activity. The mutation IVS5+3insT of GCH1 was found in 2 patients with DRD. Seven kinds of PTS mutations were found in 8 patients with PTS deficiency, and 75% of the mutations were 259C-->T,286G-->A and 155A-->G.

CONCLUSION:

Some patients with unknown motor disturbance and mental retardation may suffer from BH4 metabolism related diseases. Theses patients are necessary to be screened for such kind of diseases in order to confirm the diagnosis.

• Authors: Jun Ye, Xiao-qing Liu, Wen-juan Qiu, Lian-shu Han, Jian-de Zhou, Ya-fen Zhang, Xue-fan Gu
• Journal: Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics (Zhonghua Yi Xue Yi Chuan Xue Za Zhi) Vol. 24 Issue 2 Pg. 210-2 (Apr 2007) ISSN: 1003-9406 [Print] China
• PMID: 17407085 (Publication Type: English Abstract, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biopterin
• Phenylalanine Hydroxylase
• Dihydropteridine Reductase
• GTP Cyclohydrolase
• Phosphorus-Oxygen Lyases
• 6-pyruvoyltetrahydropterin synthase
• sapropterin

Topics

• Adolescent
• Biopterin (analogs & derivatives, metabolism)
• Child
• Child, Preschool
• Dihydropteridine Reductase (genetics, metabolism)
• Dystonia (genetics, metabolism)
• Female
• GTP Cyclohydrolase (genetics, metabolism)
• Humans
• Infant
• Intellectual Disability (genetics, metabolism)
• Male
• Mutation
• Phenylalanine Hydroxylase (genetics, metabolism)
• Phosphorus-Oxygen Lyases (genetics, metabolism)